This is a note to let you know that I've just added the patch titled
hv: kvp: Avoid reading past allocated blocks from KVP file
to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: hv-kvp-avoid-reading-past-allocated-blocks-from-kvp-file.patch and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 297d6b6e56c2977fc504c61bbeeaa21296923f89 Mon Sep 17 00:00:00 2001
From: Paul Meyer Paul.Meyer@microsoft.com Date: Tue, 14 Nov 2017 13:06:47 -0700 Subject: hv: kvp: Avoid reading past allocated blocks from KVP file
From: Paul Meyer Paul.Meyer@microsoft.com
commit 297d6b6e56c2977fc504c61bbeeaa21296923f89 upstream.
While reading in more than one block (50) of KVP records, the allocation goes per block, but the reads used the total number of allocated records (without resetting the pointer/stream). This causes the records buffer to overrun when the refresh reads more than one block over the previous capacity (e.g. reading more than 100 KVP records whereas the in-memory database was empty before).
Fix this by reading the correct number of KVP records from file each time.
Signed-off-by: Paul Meyer Paul.Meyer@microsoft.com Signed-off-by: Long Li longli@microsoft.com Signed-off-by: K. Y. Srinivasan kys@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/hv/hv_kvp_daemon.c | 70 +++++++++-------------------------------------- 1 file changed, 14 insertions(+), 56 deletions(-)
--- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -196,11 +196,14 @@ static void kvp_update_mem_state(int poo for (;;) { readp = &record[records_read]; records_read += fread(readp, sizeof(struct kvp_record), - ENTRIES_PER_BLOCK * num_blocks, - filep); + ENTRIES_PER_BLOCK * num_blocks - records_read, + filep);
if (ferror(filep)) { - syslog(LOG_ERR, "Failed to read file, pool: %d", pool); + syslog(LOG_ERR, + "Failed to read file, pool: %d; error: %d %s", + pool, errno, strerror(errno)); + kvp_release_lock(pool); exit(EXIT_FAILURE); }
@@ -213,6 +216,7 @@ static void kvp_update_mem_state(int poo
if (record == NULL) { syslog(LOG_ERR, "malloc failed"); + kvp_release_lock(pool); exit(EXIT_FAILURE); } continue; @@ -227,15 +231,11 @@ static void kvp_update_mem_state(int poo fclose(filep); kvp_release_lock(pool); } + static int kvp_file_init(void) { int fd; - FILE *filep; - size_t records_read; char *fname; - struct kvp_record *record; - struct kvp_record *readp; - int num_blocks; int i; int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK;
@@ -249,61 +249,19 @@ static int kvp_file_init(void)
for (i = 0; i < KVP_POOL_COUNT; i++) { fname = kvp_file_info[i].fname; - records_read = 0; - num_blocks = 1; sprintf(fname, "%s/.kvp_pool_%d", KVP_CONFIG_LOC, i); fd = open(fname, O_RDWR | O_CREAT | O_CLOEXEC, 0644 /* rw-r--r-- */);
if (fd == -1) return 1;
- - filep = fopen(fname, "re"); - if (!filep) { - close(fd); - return 1; - } - - record = malloc(alloc_unit * num_blocks); - if (record == NULL) { - fclose(filep); - close(fd); - return 1; - } - for (;;) { - readp = &record[records_read]; - records_read += fread(readp, sizeof(struct kvp_record), - ENTRIES_PER_BLOCK, - filep); - - if (ferror(filep)) { - syslog(LOG_ERR, "Failed to read file, pool: %d", - i); - exit(EXIT_FAILURE); - } - - if (!feof(filep)) { - /* - * We have more data to read. - */ - num_blocks++; - record = realloc(record, alloc_unit * - num_blocks); - if (record == NULL) { - fclose(filep); - close(fd); - return 1; - } - continue; - } - break; - } kvp_file_info[i].fd = fd; - kvp_file_info[i].num_blocks = num_blocks; - kvp_file_info[i].records = record; - kvp_file_info[i].num_records = records_read; - fclose(filep); - + kvp_file_info[i].num_blocks = 1; + kvp_file_info[i].records = malloc(alloc_unit); + if (kvp_file_info[i].records == NULL) + return 1; + kvp_file_info[i].num_records = 0; + kvp_update_mem_state(i); }
return 0;
Patches currently in stable-queue which might be from Paul.Meyer@microsoft.com are
queue-3.18/hv-kvp-avoid-reading-past-allocated-blocks-from-kvp-file.patch